<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        var n = parseInt(prompt("请输入一个整数"));
        function Number(a){
            var m = 1;
            for(var i=1;i<a;i++){
                m*=i;
            }
            return m;
        }
        function jc(a){
             var sum = 0;
             for(var i = 1;i <= a;i++){
                 sum += Number(i);
             }
             return sum;
        }
        alert(n + "阶乘到1的阶乘和是"+jc(n));
    </script>
</head>
<body>
    
</body>
</html>